Introduction

This is a fix for a surprise issue that I've encountered after an update of an ESET product.

For information (and the reason for this repo) check: https://forum.eset.com/topic/40702-eset-ssl-protection-produces-an-invalid-certificate-chain-for-nodejs-apps/

The Problem

ESET started replacing some certificates with their own certificates which are unknown to node. There is presently no real answer from support, no option to set an additional certificate in node, nor is there one to use a system/specified trust store.

The easy solution is to turn off the certificate check. Let's not call that one an option if we can.

We could also disable the ESET feature (but let's avoid that one too).

The solution here is to export the certificate from the Windows certificate store and set it as an additional certificate for NPM.

Steps

Step 1. Setup the Directory

The certificate needs to exist somewhere visible to node.

For the purpose of this document, let's place it in the user directory: %USERPROFILE%/certs.

Step 2. Export the ESET certificate

1. Open the certificate manager (e.g. run certmgr.msc)
2. Find the ESET SSL Filter CA certificate (or whichever is applicable to your use-case)
3. Right click, All Tasks | Export.... This will open a wizard.
4. Within the wizard, choose to export as PKCS7 with all certificates in the path.
5. Export to the new folder created in Step 1

Step 3. Convert the certificate

1. In cmd (or equivalent), navigate to the folder created in Step 1.
2. Run openssl pkcs7 -print_certs -inform DER -in exported.p7b -outform PEM -out converted.cer (thanks @nagyszabi, @ferdiusa, and @rstefko). Here it is assumed the certificate exported in Step 2 is named exported.p7b. Update the script to match your actual filenames. openssl pkcs7 -print_certs -inform DER -in exported.p7b -outform PEM -out converted.cer

Conversion Issues

Your milage may vary with the above but the general concensus seems that the current state here seems to work.

Check this issue for the latest: #1

Step 4. Store converted certificate in environmental variable

Note that the \m in the below command saves the variable in a system, rather than user context. See setx documentation.

1. In cmd (or equivalent), navigate to the folder created in Step 1.
2. Run setx NODE_EXTRA_CA_CERTS %USERPROFILE%\certs\converted.cer /m where converted.cer is the name of the converted certificate from Step 3.

Notes

OpenSSL

If you have Git for Windows, then you should have openssl (even if cmd cannot find it).

Check the install directory, e.g. C:\Program Files\Git\usr\bin\openssl.exe. Failing that you may need to install openssl.

Conversion PS Script

@rstefko provided the below powershell script in this comment.

I haven't tested it - with all things (including this readme), your milage may vary :).

$cert = Get-ChildItem -Path Cert:\LocalMachine\Root | Where { $_.Subject -like "*CN=ESET SSL Filter CA" } Export-Certificate -Cert $cert -FilePath C:\Temp\ESET-SSL-Filter-CA.cer &certutil -f -encode C:\Temp\ESET-SSL-Filter-CA.cer C:\Temp\ESET-SSL-Filter-CA.pem